The International Federation of the Phonographic Industry and the Recording Industry Association of America might sue Google, saying that the web behemoth has used its search engine service to shape the online music market in a way trade groups do not like.

These recording industry giants have pressured Google to "degrade" links to alleged "pirate" websites in search results, TorrentFreak reports. They say that Google has profited from illegal internet file sharing by failing to do so.

IFPI has now gone so far as to seek a legal opinion on the issue -- the group wants to know whether courts can make Google censor links.

The prospect of legal action is surprising -- especially considering that Google has typically been willing to work with the recording industry.

But a confidential doc examined by TorrentFreak shows that Google gave record labels a "special online interface that allows for mass queries to be marked as infringing."

The result of this interface: IFPI complained about 460,000 Google search results from August to December 2011, TorrentFreak notes, and also urged Google to shutdown "hundreds" of Blogger sites.

Because Google has not censored links to infringing content, industry groups have considered bringing the company before a judge.

"IFPI obtained a highly confidential and preliminary legal opinion in July 2011 on the possibility of bringing a competition law complaint against Google for abuse of its dominant position, given the distortion of the market for legitimate online music that is likely to result from Google's prioritizing of illegal sites," TorrentFreak notes.

More, the recording industry thinks that Google violates antitrust law by letting the algorithm do its work. The industry wants search engines to adopt a "Voluntary Code of Practice" that drives more traffic -- and ranking -- to legal file-sharing sites.

TorrentFreak claims that Google might face a lawsuit if they don't go along with these demands.